In March 2020 researchers from Thailand published the results of their study to assess the use of iodine supplementation in pregnancy A total of 208 pregnant women were involved in the study. The individuals were divided into two groups, with 104 receiving targeted iodine supplementation, ie varying concentrations based on urinary iodine levels, and 104 a fixed daily concentration of iodine supplementation. Urine samples were collected both at the start of the study and at the time of delivery. The iodine levels at the start of the study were not significantly different between the two groups, with over half of the pregnant women being classified as having iodine insufficiency. Results showed that both types of iodine supplementation were equally effective in preventing iodine deficiency although the supplementation with varied concentrations of iodine was better in avoiding over supplementation.
Tinna T et al. Comparison of the Effectiveness of Universal and Targeted Iodine Supplementation in Pregnant Women: A Randomized Controlled Trial. Gynecol Obstet Invest. 2020;85(2):189-195.